This article discusses the application of computational fluid dynamics (CFD) to calculate the three-dimensional isothermal airflow in an industrial electrical forced-convection oven. The governing fluid flow equations were expanded with a fan model and a turbulence model. The standard and the renormalisation group (RNG) version of the k-epsilon turbulence model produced comparable results. The performance of the CFD model was assessed by means of point measurements of the velocity with a directionally calibrated hot-film velocity sensor. From the validation it was found that important aspects of the model are the fan head-capacity relationship, the fan swirl and the oven geometry. The calculation error was on an average 22% of the actual velocity, caused by the limitations in turbulence modelling and numerical grid density. (C) 2000 Elsevier Science Ltd. All rights reserved.